Windows server R2 Hyper-V (known?) issue with Virtual Switch

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lyonrouge

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#82539 1-May-2011 10:28

Is there a known problem in Windows Server 2008 R2 SP1 (not upgraded, installed from image that includes SP1) with Hyper-V virtual switch? When I enable Hyper-V and a external network (bound to phyiscal) it moves the Static settings from the phyiscal adapter, causing all connection to be lost. So I moved the static settings back the physical but the virtual switch is unable to obtain settings from the DHCP server.

I have a Hyper-V already active and it works fine with the same configuration, however, it was installed on Windows Server 2008 R2 without SP1 and upgraded to SP1 later.

lyonrouge

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#464116 1-May-2011 11:31

I had two network adapters on the machine, so removed one and reinstalled from scratch. Configured static IP on the adapter and added to domain. Applied available updates (restart) and enabled Hyper-V, same configuration change applied again, causing pretty much every network based feature to fail or extremely slow (SMB fail, de-registration from domain, very very slow). Scrubbing the machine again and trying Windows Server 2008 R2 (excl SP1) ...

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lyonrouge

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#464124 1-May-2011 11:58

no different without SP1 image, I'm pretty much stumped now, I've only installed this once before so I'm going to guess what I did right with the first one and try a few changes.

boby55

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#464127 1-May-2011 12:02

Hmm, I have never come across that before and I've done 3-4 Hyper-V Setups. Are the Network Card drivers up to date?

lyonrouge

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#464129 1-May-2011 12:06

yes. MS certified drivers installed. Base install is clean, all events are info only, certain it's a hardware issue somewhere, I'm pulling parts out of it now.

lyonrouge

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#464130 1-May-2011 12:07

tried forcing (static IP) the configuration to best match the working instance but no luck, I can tell it's broken again as it is stuck on "applying computer settings"

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#464131 1-May-2011 12:10

What happens when you change the adapters around?

lyonrouge

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#464138 1-May-2011 12:16

funny, great minds huh? just done that and installing WS2K8R2SP1 image now

lyonrouge

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#464149 1-May-2011 12:54

magic! (no, really, it does appear to be some kind of magic), working this time with the other adapter, although the configuration is very different to the other Hyper-V server, I'm not messing with it because it is working.

I wonder if it's a similar characteristic requirement of the adapter that is needed for WinXP bridging?

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#464264 1-May-2011 20:44

when you enable hyper-v virtual switch for an adaptor, the bindings are removed from the physical adaptor and - assuming you selected "share with management os" - you get a new virtual adaptor to use in the host OS. The physical adaptor will only ever have the virtual switch bound to it.

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lyonrouge

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#464379 2-May-2011 09:19

thanks, found that one of the ethernet adapters would not support the virtual switch protocol. my (unsubstantiated) theory is that like connection bridging, a hardware requirement surrounds the virtual switch protocol which is not tested during installation. Each test I ensured only 1 card was installed, the configuration then automatically enables "allow management operating system to share this network adapter". The first card (Realtek RTL8169/8110) would not work after configuration applied, where the second card (Realtek RTL8168D/8111D) does work. So I've addressed the symptom, but I'll continue to research the cause, and maybe submit to MS a compatibility check for role installation software, or maybe just a blog entry.

lyonrouge

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#477294 3-Jun-2011 08:18

Can now verify that Realtek RTL8169/8110 will not work as the Virtual Switch adapter, just got another box (i7 this time) and installed Hyper-V with the same symptoms, looked at the adapter, and what do you know, the same one.

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#729547 10-Dec-2012 09:57

Hi lyonrouge, you wrote "Can now verify that Realtek RTL8169/8110 will not work as the Virtual Switch adapter". Thanks for your post. I had the same experience. In short, a Realtek PCI card wouldn't work no matter what tweaks I tried but then as soon as I changed to using an Intel Server Pro PCIe NIC the virtual networking worked fine.

Details: running Windows Server 2008 R2 Hyper-v, using an RTL819-based PCI-card NIC dedicated to the virtual network. The virtual network comms worked fine with XP VMs but as soon as I tried to add in a Windows 7 VM all the virtual network comms ground to a halt. I tried to fix it by disabling the TCP offload but that didn't help. Changed the card then everything perfect

lyonrouge

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#729956 10-Dec-2012 20:23

Thanks, useful to have another user verify my findings.

lyonrouge

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#777682 10-Mar-2013 17:57

Regs: when you enable hyper-v virtual switch for an adaptor, the bindings are removed from the physical adaptor and - assuming you selected "share with management os" - you get a new virtual adaptor to use in the host OS. The physical adaptor will only ever have the virtual switch bound to it.

It appears that the "share with management os" requires a feature that the RTL8169 does not support. I can use these NICs for Hyper-V virtual switches, but not when integrated back into the LAN.

lyonrouge

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#794814 8-Apr-2013 08:24

Just did another build and migration, and found another issue with RTL8169. As per previous posts, this cannot be used as "share with management os" adapter. After migrating I found a long running issue I had with UDP traffic traversing a Virtual Switch appears to have been fixed. The root cause appears to be again the RTL8169. When I pulled apport the decommissioned Hyper-V host I found that this adapter was the one giving me UDP grief.

So in summary don't use a RTL8169 for

management adapter
UDP network

basic TCP seems fine.